Tube-bending machine



Filed June 3, 192s 7 Sheets-Sheet May 2l, 1929. L, FRANK 1,714,083

TUBE BENDING MACHINE Filed June I5, 1926 '7 Sheets-Sheet 2 Mayh 21, 1929. L. FRANK 1,714,083

I TUBE BENDING MACHINE Filed June 5. 1926 v sheets-sheet 3 l /J Mmmm@ V INVENTOR aa/s- Fia/wf ,w 'y /25 ATTORNEY May 21, 1929.

l.. FRANK TUBE BENDI'NG MACHINE Filed Jurk@ s. 1926 "r sheets-sheet @Tirilli INVENTOR aa/.5 /C/sw/f ATTORNH May 21, 1929. FRANK 1,714,083

TUBE BENDING MACHINE Filed June 3, 1926 7 Sheets-Sheet 5 INVENTOR 0a/.s @fsw/f ATTORNEY May 2l, 1929. vl.. FRANK 1,714,083

TUBE BENDING MACHINE Filed June 3, 1926 'T ShQets-Sheet 6 ATTO R'N EY INVENToR [0d/- ,Cha/y BY Y May 21, 1929.v 1 FRANK TUBE BENDING MACHINE '7 Sheets-Sheet 7 Filed June 3. 1926 NQ mw ATTORNEY Patented May 2l, 1929.

UNITED STATES PATENT oF FICE.

LOUIS FRANK, OF FLUSHING, EW YORK, .ASSIGNOR T0 GREENPOINT METALLIC BED CO., INC., 0F BROOKLYN, NEW YORK, A CORIORAQTION NEW YORK.

TUB-BENDING MACHINE.

Application led June 3,

This invention relates to metal tube or pipe bending machines of the type wherein a tube or pipe may be bent to a desired shape without deforming its cross-sectional configuration, and without injury to its molecular structure.

The invention contemplates a machine wherein a pair of forming members are mounted in opposed relat-ionship for engaging opposite sides of the pipe or tube to be benf, one of said forming members having a profile corresponding to the desired bend,

and preferably having mounted with it a tube clamping, vise. The profile forming member and the vise are movable preferably by oscillation about a fixed axis, and the other forming member lwhile firmly maintained against'the -tube, may preferably be 'free to float or move in a path substantially tangent to the travel of the profiled edge 'of the first forming member. When the bend to be produced is a compound, eccentric orrotherwise irregular curve, one'of the forming members is preferably moved laterally with respect to the other tocompensate for such irregularity, and for this purpose a suitable cam may be employed for synchronous operation with the profiled forming member. To facilitate insertion and removal of the work the pref erably free or floating forming member may be withdrawn from its position in opposition to the other forming member, and furthermore, to increase the usefulness of the jaws for accommodating the work in different stages. The tube being operated upon may l, be protected ,from Acrumbling by suitable ,means such as a flexible mandrel `inserted Within the tube, and may' be 4further restrained from outward bulging by confining ormmg memit in a .groove in the proled ber, the bottom of the groove having the desired curved profile and the side walls of the groove being formed by flanges, one of which may preferably be movable away from the other for releasing the tube after the bending operation is completed. Various adjustmentsv are provided whereby the machine is capable of operating on diii'erentsizes of -tubmined degree to showing a vise 1926 serial No. 113,365;

ing and the whole assemblage is such as to constitute a substantial advance in the art.

An importantobject of the invention is to a'provide a machine for accurately bending thin walled metal tubing to a desired shape withoutinjuy to the walls ofthe tubing; and a more special object is to'provide such a machine for the production o'eccentric, compound o r otherwise irregular curves in tubing such as used in making the ends of the head and foot pieces o f metallic bedsteads, which have two such bends connecting the zontal portion.

' Other objects. are to provide a machine which is adapted to efficiently and in a simple manner produce a smooth bend in metal tubing, the machine being of suchv a nature that more or' less unskilled labor may control and o'perate it, and to provide such a machine capable of operating on different sizes of tubing as desired.

These being among the objects of the present invention, the same consists of certain features of construction and combinations of parts lto be hereinafter described and. then claimed withrefere'nce to the accompanying drawings illustrating a preferred embodiment-of the invention, and in which:

Fig. l is a planof the improved bending machine showing a straight metal tubing in position to be clamped preliminary to forming the first bend;

Fig. .2 is a plan of the machine showing the tubing, after it has received its iirst bend, placed in the machine and clamped in position ready to produce the second bend; i

Fig. 3 is a plan of the machine in which the tube carrier has been rotated to a predeterproduce the second bend in the tubing;

Fig. 4 is a vertical central section of the machine showing the tubing clamped therein;

Fig. 5 is a section on the line 5 5 Fig. 1; 6 is a horizontal section on the line 6 6 Fig.7 is a section on the lineJ 7 7 Fig. 1

preliminary to the first end;

Fig. Sis a transverse section on the line 8 8 rigged u to clamp the tubing 2 posts or uprights' with the transverse or horii Fig. 3. showing thel vise as it is rigged up to clamp the tubing at its first bend while producing the second bend;

Fig. 9 is `a sectional plan of the forming lhead of the'tube carrier, partly broken away .-on the line 15-15 Fig. 9; and

Fig. 16 is a detail sectional, view showing a flexible mandrel within the tubing preliminary to bending. y

Referring to Figs. 1, 4, 5 and 6 of the drawings in particular, the machine is driven by a shaft 10 on which is fixed a double friction cone 11 in a well known manner so as to permit the cehe to be moved lengthwise and yet be rotated by the shaft 10. -Cone pulleys 12, 13 are mounted loosely onr the drive-shaft 10, so that the double friction cone 11 is located between them. A flat belt 14 is trained on pulley 12 for forward driving movement of the machine, and a similar belt 15 is trained on pulley 13 and crossed for a reverse driving movement. Bearing blocks 16, 16a are provided and therein the shaft 10 is journalled.

As more particularly shown in Figs. 4, 5 and 6, the main portion of the machine 'is pros vided with a base 17 which carries uprights or frame sections 18, 19, 20 bolted or otherwise rigidly secured t0 the base 17. Said uprights support a table top or platform 21 which may be of any preferredshape most suitable for the work to be performed. A. vertical spindle 22 is journalled in a step bearing 23 at the base of the machine and its upper portion is reecived in a bearingl 24 at the table top or platform 21. A large speed reducing gear- Wheel 25 is rigidly keyed or otherwise permanently secured to the spindle 22.

In order to slowly .turn the gear-wheel 25 from either one of the belt pulleys on the drive-shaftl 10, suitable speed reducing macchanism is provided. The pulleys 12, 13 are shown as mounted at that end of the shaft 10 which is outside the frame proper of the machine, and the other end of the shaft 10 is Y provided with a bevel-pinion 26 rigidly secured thereto. This pinion 26 is in lconstant mesh with a bevel-gear 27 which is rigidly secured to a shaft 28 journalled in a bearing block 29 and in the upright 20 of the frame. Shaft 28 extends at right-angles to the driveshaftlO and is provided at its outer endwith a pinion 30 which is in constant mesh with a gear-wheel 31 rigidly secured to a countershaft 32 also journalled in the frame upright 20.

The inner end -of the counter-shaft 32 is provided with a bevel-pinion 33 which is in constant mesh with a bevel-gear 34 adaptedto turn on the shaft 35 mounted rigidl on the base and table top of the frame o the machine. Bevel-gear 34 may be suitably constructed to rest u on a collar 34al rigidly secured to the uprig t shaft 35. The bevel-gear gear 25, all being driven as parts of saidtrain in the order enumerated. The operation of the described driving mechanism will be detailedmore particularly hereinafter.

With more particular reference to Figs. 1,- 2 and 3, the tube carrier and concomitant parts will noW be described. The forming head 39 of the tube carrier is keyed to the upper end of the spindle 22,. so that it may be oscillated or swung within redetermined limits iu a horizontal plane Just above the table 21. The forming head 39 may be constructed in any preferred manner so as to provide a tube receiving recess 40 on the formingl portion of the head and away from the axls of the carrier spindle 22, the recess being so constructed that the bottom thereof, as indicated indotted lines, conforms to the desired bend to be produced in the tubing. In the embodiment of the invention as shown the length of the recess and its curvature are such that two eccentric bends may be made in metallic tubing as, for instance, for bed ends vof pieces. In Fig. 1 that portion of the eccentric curve of the recess 40 which is actually involved in forming a single eccentric bend in metal tubing is indicated at one end approximately by the numeral 41 and at the other end approximately by the numeral 42, the extent being such as to cover 4about`90 degrees or the lpredetermined arc of movement of the tube carrier.

4The under side of the-formin head 39 is provided with a rigidly mounted cam member 43, vthe prole o f which, at its inner curvature, shouldsubstantially correspond with the eccentric curvature of the bottom of the tube 4recess 40,from 41 to 42, as shown more clearly in Fig. 4 to which reference may also be had. The cam member 43 is -secured to the under side of the forming head 39 set-screws 44.

by means of Mounted ,to slide on the table or platform 21 is aslide 45 which is adapted to be moved in a direction radial of the axis ofthe carrier spindle 22, and to that end said slide 45'is guided in ways'46 fixed to the table 21. The inner end of the slide 45 is provided with a fixed stud which extends upwardly towards the forming head 39, there being journalled on it an anti-friction roller 48 which is always in contact with the profiled inner face of the cam 43, so that when the forming head moves through its predetermined range of oscillation, the profiled inner face ofthe cam 43 will cause a movement of the slide`45 which is controlled by the cam.

A carriage 49 having a limited travel has a dove-tail sliding connection with the guides ing the bend in the tubing. The jaws 56 are v46, as shown more clearly in Fig. 14. The outer end of the aforesaid slide 46 carries a post 50, which is received in a slot 5l of the carriage which extends parallel with the slide 46. Said post is provided with a flange 52 to bear on the bottom of the carriage 49'at both Sides of the slot 51. The other end of the post 50 is reduced and screw-threaded and receives a washer 53 and a screw-threaded nut 54 which is adapted to so secure the washer 53 that it, with the flange 52, is adapted to be bound together against the upper and lower surfaces of the carriage, at both sides of the slot 51. In other words, by means of the pin and slot connection as it were, furnished by the post 50 and the slot 51, the carriage is adapted to be adjusted and set in a definite relation with respect to the slide 46, and the setting of the parts after adjustment is more definitely determined and obtained by means of a screw-threaded adjusting spindle 55 which is provided at its outer end with a wrench-head adapting it to be turned. To

obtain the desired adjustment ofthe carriage,l

the nut 54 is released so that the adjusting spindle 55 may be operated to adjust the carriage, and the desired position of the carriage relative to the slide 45 having been obtained, the nut 54 is again tightened.

Carriage49 is provided with a pair of jaws, or j aw-like projections 56 in which turn antifriction rollers 57 which are located at the opposite side of the gap, from the forming head 39, into which certain parts to be hereinafter described are introduced with al view to formconnected by a member 58, located inwardly of'but parallel with a flange or wedge 59 of "the carriage 49. suchflange extending at right-angles to the line of movement of the carriage and the slide 45. The connecting m mber 58 and the' jaws 56 with their rollers G0 s? are mounted on the carriage for movement with respect to the ange or wedge 59.' To this end, screw-threaded headed pins 60 extend through the flange59 and the jaw connecting member 58, the unheaded ends of said pins being provided wtlrnut's 62 screwed thereunto, while helical expansion sprin s 61 are coiled about said pins/1 at their hea s in such way as to tend to resiliently move the through the medium of substantially halfround stepping cams 63 in the form of posts and which are mounted in curved recesses 64 in both ends of the carriage 49, said cams being operable through the mediumA of hand cranks 65. In Fig. 1 the hand cranks 65 are shown as extending in opposite directions in which case the springs 61 move the jaws 56 up .to the carriage; In Fig. 2 the hand cranks are shown in broken lines each having been moved through an angle of degrees so as to press the jaws 56 away from the carriage, thus compressing the springs 61.

In Figs.' 1 to 4, inclusive, there is shown a forming member 66 and which consists ofa straight bar of metal provided with a rigid. Y

handle 67. This metallic forming member 66 it may be moved by an attendant -of the machine when he grasps the handle 67, whereby he may slide theyforming member 66in one direction or the other. The forming member or bar 66 is supported on an accessory table or platform 68, preferably in the form of an elongated bench, the upper surface of which may be lubricated with graphite or the like, so as to permit an easier movement of the forming member. When the machine is to' make a bend in metal tubing, this forming member orbar 66 is slid by an attendant into the gap between the forming head 39 and the carrier jaws 56, as more specifically explained hereinafter.

Referring more particularly to Figs. 1, 7 and 11, a clamping member 69 is provided consisting of a suitablyshaped metallic block, f which constitutes one of the members of a substantially meet atthe smaller end of the I member. The curve 72 of the member 69 is such as to constitute substantially a continuation of the curve of the bottom of the recess 40 in the forming head 39, when the clamping member 69 is inserted in the outer end of the said recess with its pin 71 seated in a corresponding socket in the forming head, as' shown in Fig. 7. This positioning of the clamping member 69 places its straight edge 73 tangential to the curve of the bottom of the recess 40 and provides a straight extension from said recess, for the purpose to be hereinafter explained. f

tudinal recess 76, with a straight bottom, in-

that/ face or edge which is to oppose the straight edge 73 of the clamping member 69.

At one side of the recess 76 there extends from one wall of the recess in a plane at right-angles to the plane of the recess, a flange 77.

" The clamping member 74 is provided at that side opposite to the handle 75 with a pin 78, later on again referred to.-l -The described clamping members 69 and 74 are adapted to .clampa straight portion of the metallic tublng.

Referring more particularl to Fig. 9, the vise of which clamping mem ers 69 and 74 are adapted to form parts, is provided with a base-plate 79 which may be rigidly or removably secured to the formino' head 39 by means of fastenings 80. The is thickened -at one end and provided with a shoulder 81 which is adapted' to abut against one end of the forming head39, so that in connection with the fast-enings 80the2 baseplate of the vise is firmly secured in position at that end of the forming head which con.

stitutes the advancing end of the head. The baseplate 79 is provided with a groove 82 which constitutes an extension of the curved receiving recess of the forming head of the base-plate 79 (see Fig. 7) 4 It will be seen that'when the vise referred to is equipped with clamping members 69 and 74, as shown in Fig. 1, the straight outer end of the metallic tube may be clamped so that it will extend tangentially with respect to the curved bottom of the recess 40, from approximately the point 42.

A swinging arm 83 is pivoted at one end to the base 79 of the vise and is provided at its free end with a threaded eye 84 which receives a screw spindle 85 provided with a handle 86 at its outer end and a pressure head 87 at its inner end. This swinging arm 83 is'in outwardly swung position in Fig. 1, but in Fig. 2.it has been shown in operative position. Y

As shown in Fig. 7, the base-plate 79 of the vise is provided with a slotI 88 for receiving the pin' 78 on the clamping member 74 of the vise. Auxiliary vise means are illustrated comprising a manually operable handle 89 fulcrumed on a piyot stud 90 rigid with te base-plate 79, and at the opposite side of t e stud 90 from the handle 89, the hub or head of the handle is provided with a knuckle 91 having a curved engaging edge for setting in a correspondingly curved recess in a chock 92, comprising a body 93 and an angle-member 94. Angle-member 94 is adjustable throughthe medium'of adjustin screws 95 which pass through one ange o the angle- Imember and the body 93, the adjustment bease-plate. 79j

ing he' `by means of-thrust screws 96 which are loI ted under the other flange of the an-l gle-member and are screwed into the body 93. It will here be noted that when the visearm 83 is locked in position and the handle member 89 operated so asto throw the chock 92 from the position shown in Fig. 1 to that shown in Fig. 2, that the metal tube is held fast. It may here be stated that Fig. 1 shows the parts of the machine in position with the tube placed so that when the machine is s'et to hold the tube, the forming head may be turned. so as to produce the first bend in the tubing. The drawings therefore do not show a straight tube which` has not 'been bent clamped in. position for the first bending operation, nor the osition ofthe forming head when the first end is produced; except that Figs. 2and 3 show the machine adjusted and adapted to form the second bend, and except for the difference of set-up of the parts, such as forming members and the like, these Figs. 2 and 3 show all that is necessarylfor a complete understanding of what follows when the mechanism as shown in Fig. 1 is adjusted for holding the tube preliminar to and during the making of the first bend.

Means are preferably provided to enable a metal tube to be inserted readily inthe recess A40 of the forming head 39 and to be removed as readily after a bend has been made. To

that end means may be provided, such as shown in Figs. 1, 5 and 15, wherein a clearance member or flange 97 is the forming head 39 to constitute the ,outer4 side wall of the' eccentrically curved -recess 40. This clearance member 97 may be moved slightly away from the opposite wall of the recess in order to increase the width of the 'recess for the free entrance of a metal tube,

projecting pivot-studs 98 set back of ther working edge of the forming head in substantial parallelism with the curvature of the bottom of the recess 40, and a series of rock--l arms 99 are rigidly secured .at their inner ends on the studs 98. A series of links 100/ pivotally connect the rock-arms 99 with each rovided upon other, so that a movement f one arm will 120 cause all the other arms to follow. A handlever 101 is rigidly/secured' t'o one of the pivot-studs 98, which studs are screw-thread2 shown in Fig. 9 to the position shown in ,'Fig. 1, the springs act automatically to cause an outward movement of the clearance mem- CII ber, and hence the widening of the recess 40 in the forming head 39. A metal tube may then be readily inserted into the recess in the forming head. V

Referring to Figs. 4, 5 and 6, mechanism is shown more clearly for operating the clutch 11. This mechanism comprises a slide-rod 103 mounted for a sliding movement in the bearing blocks16, 16a and it carries a yoke 104 for operating the friction cone or clutch 11 in the usual manner that is to say, the yoke has projections talien into an annular groove in the clutch 11, permitting the latter to turn with the drive-shaft 10. The other provided for the purpose of rocking the fork 107 in one direction or the other, depending upon the direction in which the sliderod 103 is to be operated, for the purpose of engaging the friction cone or clutch 11 with one or the other of the belt pulleys 12, 13, depend-.

ing upon the direction in which the mechanism of the machine is to be operated.

The machine is furthermore provided with means for automatically throwing the friction cone or clutch 11 out of engagement with one or the other of the belt pulleys 12, 13, such means comprising a tappet-arm 110 and another tappet-arm 111, the two arms being formed as an angle-member which is secured at yits angle-portion upon the spindle 22. For engagement with one or the otherof the tappet-arms 110, 111, the Slide rod 103 1s provided with an abutment pin 112. Briefly, the hand-lever 109 manually controls said automatic throw-out or disconnecting means, while one of the tappet-arms is adapted'to come in contact with the abutment 112 when the machine is moving in one direction and the tappet-arm 111 to also come in Contact with said abutment when the machine is running in the other direction, each tappet-arm functioning so as to shiftthe friction cone or clutch 11 and disconnecting it from that belt pulley with which it may be connected.

Themandrel and withdrawal mechanism is more or less common in the art, the mandrel being arranged upon the bench or table 68 in position for use and the feed mechanlsm being under control of 'ne drive-shaft 10 of the n l l l l l l l machin The metallic mandrel 1s shown 1n Fig. 16' nd comprises a flexible section or block 113 and a rigid section or shank 113 which carries the iiexibly connected sections 113. The rigid section or shank 113* is at-l tached to a wire cable or rope 114 which is connected with the more or less well known mechanism which controls the feed of the mandrel, as before mentioned. The described mandrel 113, 113a is forced into the metal tube 115 which is to be bent by hand, it beingcustomary to smear a suitable -lubricant into the flexible portion 113 while the mandrel is resting on the` bench or table'68, so as to enable an easier introduction of the mandrel into the tube for the lexiblemember or section 113 and is of hard metal and has a very tight iit in the tubing. After the metal tubing 115 has been bent, the mechanism connected with the cable 114 automatically pulls the mandrel out of the tubing. It will be noted that the flexible member or sction 113 of the mandrel supports the walls of the tubingr 115 while it is being bent, t e bending taking place between the opposing faces of the forming head of the tube carriei and the forming member 66, which member uis carried to the right with reference to Fig.

3 during the act of bending, and when the bend has been completed, the movement of theforming member 66 is arrested by a stop 116 on the forming member 66, which'stop then abuts-against the adjacent jaw 56 Aof the carriage or slide 49.

When the bending member 66 is out of use, it is slid out of the machine and along the bench or table 68. In the operation of the machine the attendant grasps the handle 67 and slides the forming member 66 so as to bring its inner end into the gap between the recessed face of the forming head 29 and the rollers 57. In adjusting the machine for producing the first bend 117, indicated in Fig. 2, the bending members of the machine will first be adjusted to the position shown in Fig. 1. The clearance member 97 will be in slightly raised position so as to enable the metallic tube 115 toy be readily introduced into the re-l cess 40 of the forming head. The tubing 115 having been thus introduced into the forming recess, the operating handle 101 of the clearance member 97 is moved from the position mechanism may be omitted, in which case the forming recess 4:0 could have three vrelatively stationary walls. between which the metal tubing 115 may be operated upon. It will lie seen that when the metal tube is introduced between the\forming head 39 and` the forming member 66, the tubing will be in ,Contact with the opposing faces of the vise previouslydescribed, comprising the clamping members 69 and 74, the clamping member 74 being then loose, and unclamped. he attendant of the machinethen swings the arm 83 from the position shown in Fig. 1 to that shown in Fig. 2 and turns the handle 86 so as to cause the head 87 of the screw 85 to rmly engage the clamping member 74, shown in Fig. 1, whereby a vise grip is established by the two clamping members 69 and 74 upon the metal tubing 115. The attendant then swings the handle lever 89 from the position s hown in Fig. 1 to that shown in Fig. 2, when the clamping member 74 is more rigidiy and firmly held than it would be by the mere clamping action of the head 87 of the screw spindle. A firm rigid grip on the lnetal tubing 115 must be had by the vise. before the machine is caused to operate. The attendant furthermore moves the handles 65 from the positions shown in Fig. 1 to those shownin Fig. 2, thereby compressing the springs 61v and pressing the anti-friction rollers 57 against the forming member or bar 66, thereby establishing a firm contact between the forming bar 66 and the tube, and between the tube and the bottom of the forming recess at 42 (Fig. 1).

The forming elements of the machine having thus been adjusted and set, the'machine is in a condition to be operated. The attendant moves the handle 109 so as to bring the cone or clutch 11 into clutching engagement with the belt pulley 12, so that the power transmitting mechanism of the machine will be operated by the drive-shaft 10 and will turn the large gear 25 in the direction of the arrow (Fig.` 6), thereby rotating the spindle 22 and the tube carrier through an arc of approximately 90 degrees, and at the completion of this turning movement the tappet 111 is brought into contact with the abutment 112, resulting in disconnecting the clutch 11 from the belt pulley 12 and stopping the machine automatically. It will be understood that when the operating parts appertaining to the bending act. and which are shown in Fig. 1. are adjusted and set as before described, the first bend 117 is made in the tubing 115 when the tubf forming head 39 of the tube carrier isoscillated on the axis of the spindle 22 through the aforementioned are. The eccentric contour of the forming face of the head 39 is such that an eccentric bend 117 (the first bend) is made in the `metal tubing. the outer end of this tubing being firmly held in the vise which carries that end through the described arcuate range of movement. The portion of the tubing which is to receive the first bend 117 will be acted upon by that length of the forming face of the head 39 which is located approximately between the points 41. and 42 in Fig. 1, and that portion of the forming face will roll upon the corresponding length of tubing to be bent and actin the nature of an anvil, around which the bend is formed. Also during the arcuate movement of the forming head, the profile of the cam 43 thereon acts upon the roller 48 so as to move the carriage 49 with the movement in consonance-with or corresponding to the extent of departure of the eccentric face of the head 39 from its shortest distance from the axis of the spindle 22 to the longest distance from said axis. In this way the profile of the cam 43 will always cause the anti-friction rollers 57 of the carriage/49 to be kept in contact with the corresponding edge of the forming member or bar 66, thereby offering the proper amount of resistance to any movement of said formmg member or bar away from the forming face of the head 39. During this bending movement, the forming member or bar will be caused to move to the right of Fig. 1, until the stop 116 strikes the jaw 56 of the carriage 49, when further movement of the member 66 will be arrested. and the machine will at that time also be brought to a stop by reason of the clutch 11 being automatically disconnected from the belt pulley 12. I

When the operation of the machine in forn'iing the first bend 117 is arrested, the forming head 39 is caused to have a reverse movement. The attendant will shift the handle 109 so as to bring the friction cone or clutch 11 into operative engagement with the belt pulley 13, the tappet being then 1n contact with the abutment 112. This will effectuate a reverse movement of the forming head 39 to bring the forming head, the vise and the forming member 66 back to their original positions, but the mandrel control mechanism will still be in operation, and the mandrel will be forcibly withdrawn from within the bend in the tubing and freed from the tubing until the flexible member thereof rests upon the bench or table 68, when the movement of that mechanism is arrested. The attendant then releases themembers of the vise from their hold on the tube and the formmg member 66 is also moved further away onto the bench or table 68 so as to draw it out of the gap between the forming head and the carriage 49, the operator first actuating the handle 65so as to release the formlng member 66 from the jaws 56 and their rollers 57. The clearance member 97 is now released from its hold on the metal tubing, by the operation of the handle 101. The

metal tubing with the first bend therein can,v

now be readily withdrawn from the machine.

If a second bend is to be made,l as would be the case when the tubing is to be bent for the formation of the head and foot portions of bedsteads, clamping members shown in Figs. 12 and 13 are applied to the machine,

which conform at their gripping faces with the contour of the. first bend, as they preferably grip the tubingat that bend. In Fig.

2 the substitute clamping members are shown in position for clamping the tubing at the'A linto the hole at the bottom of said recess.

The outward curve of the clamping member 118 constitutes a continuation of the bottom of the recess in the forming head 89' and conforms to the eccentric curvature of the inner bend of the tube portion 117. The

clamping member 12() is adapt-ed to be arof the concave face 122 and with a pin 125i projecting from the bottom of the clamping member. The clamping member 120 is recessed upon the base-member 79 of the vise with its pin 125 entered into the slot 88 of the base of the vise, its inwardly curved face 122 opposing the outward curve of the clamping member 118, its fiange 123 being engaged under one side ofthe' bend 117 of the metalv tubing. When the clamping members are properly adjusted at opposite sides of the bend 117 the swinging arm 83 is moved over so that the attendant may, by turning its handle, cause the head 87 to firmly bear upon the straight edge 124 of the clamping member 120. Next,'the hand lever 87 is operated so as to cause the chock 92 to also firmly bear upon the straight edge 124 of the clamping member 120. Of course the other parts which have to be manipulated in. order to enable the introduction of the metal tubing and the adjustment tothe working' position have to be adjusted and fixed after adjustment as described in connection with the formation of the first bend. The metal tubing will then be firmly gripped in themachine at the first bend 117, as shown in Fig. 2, and the machine is ready to be operated so as to turn the forming head through an angle of approximately 90 degrees about the axis of the spindle 22. The machine is then operated as before described for producing a bend in the met-al tubing and when the forming head 39 has arrived at approximately the position shown in Fig. 3, the seoond bend 126 will be complete in the metal tubing. The machine is then reversed, as before described, after which the mandrel is removed from the tubing. By some such operations as before described, the desired curvature of the head and foot portions of metallic bedsteads, for example, `may be produced in an economical and expeditious manner by the machine of the present invention.

If desired, the forming head 39 may be equipped with an additional vise for gripping the outer straight portion 150 (Fig. 2) of the tubing during the formation of the second bend, and thereby positively preventincr deformationl of the first bend during the subsequent operation. Furthermore, the cam 43 which controls the carriage 45, may be replaced by any other suitable type of cam which is synchronized in its movements with the forming head, but not necessarily mounted co-.axially therewith.

It is obvious that the invention is susceptible of a wide range of modification other than those specifically mentioned and still be within lthe spirit and scope of the appended claims.

Having thus described my invention, what I claim is: 4

1. In a tube bending machine, the combination of a pair of opposed forming members, one of which has a profile the same as the desired bend, means for holding a tube to be bent, between the opposed forming members and in fixed relation to the profiled member,

and means for imparting a tangential movementandalso va lateral movement to one of the forming members relatively to the other forming member during the bending operation.

2. In a tube bending machine, the combination ofa pair of opposed forming members, one of which lhas an eccentrically curved proe file corresponding to the desired bend, means for holding a tube to be bent, between the opposed forming members and in fixed relation to the profiled member, means for imparting atangential movement to'the .other forming member relatively to the said profiled forming member, and means for moving said other forming member laterally during said tangential movement.

3. In a tube bending machine, the combination of a pair of opposed forming members, one ofwhich has an eccentrically curved profile-corresponding to the desired bend, means for holding a tube to be bent, between the opposed forming members and in fixed relation to the profiled member, means for turning the profiled member about a fixed axis, and a cam operable with said profiled member for moving the other forming member laterally during said turning movement.

4. In a tube bending machine, the combination of a pair of opposed forming members, one of which has a curved profile correspondv substantially straight and free to move loning to the desired bend, and the other being gitudinally, tubegripping means fixed to saidy profiled forming member and adapted to hold a tube to be operated upon, .between the opposed forming members, means for imparting arcuate motion to the profiled forming member and tube gripping means lto bend a tube held therein, and means to laterally move the longitudinally movable forming member 4to correspond with the curve of the profiled forming member.

5. In a tube bending machine, the combination'of a pair of opposed forming members, one of which has an eccentrically curved profile corresponding to the desired bend, and the other being free to move longitudinally, tube gripping means fixed to said profiled forming member and adapted to hold a tube to be operated upon, between and in engagement with said curvedV profile and a side of the longitudinally movable forming member, means to rotate the profiled forming member and tube gripping means through the are of a circlefand exerting a rolling pressure on the tube, and means for moving said longitudinally movable forming member laterally to compensate for the eccentricity of the bend.

6. In a tube bending machine, thecombination of a rotatable forming head having a curved profile, a straight forming bar opposed to the curved proiile of said forming head and rspaced from said curved profile a distance equal to the width of a tube to be operated upon, a cam rotatable with the forming head, a carriage for acting upon the straight forming bar 'and controlled by the cam, tube gripping means carried by the forming nhead, and means for rotating the forming head through the arqof a circle whereby to benda tube to the curved profile of said forming head.

7. In a tube bending machine, the combination of a rotatable forming head having a v curvedprofile, a straight forming bar opposed to, the curved profile of said' forming head and spaced from said curved profile a distance equal to the width of tube to be operated upon, a cam. rotatable with the forming head, a carriage for acting upon the straight forming bar and controlled by the cam, tube gripping means carried bythe forming head, nfand means for rotating the forming head `through the arc of a circle, the straight form- 5 ing bar being free to move longitudinally Wherebyto exert a rolling pressure on a tube gto bend it to the curved profile of ysaid form- 8. In a tube bending machine, a forming head having a grooved edge for reception of a tube to be bent, the bottom of the groove being curved to correspond With the desired bend, a forming bar opposed to said grooved' edge for confining a tube in the groove, said for movement with the forming head, means y for rotating the forming head and tube clamping means through an arc of a circle, and means for automatically arresting the movement of said parts at a predeterminedy limit.

9. In a tube bending machine, Va forming head having a profiled edge corresponding to the bend to be produced, a longitudinally movable forming member opposed to said profiledwedge for forcing a tube against the same, tube clamping lmeans mounted for movement With the `forming head, means for rotating the forming head and tube clamping means through an arc of a circle, and means for automatically arresting movement of said parts, including the longitudinally movable forming member, at a predetermined limit of movement. l

10. In a tube bending machine, a forming head having a grooved edge for reception of a tube to be bent, the bottom of t-he groove being curved to correspond with the desired bend, a forming bar opposed, to said 'grooved edge for confining av tube in the groove, .said forming bar being freely slidable tangentially with respect to the grooved edge of the forming head, tube clamping means mounted for movement with the formhead and tube clamping means through an arc of a circle, means for simultaneously moving the forming bar laterally with respect to the axis of the forming head, and means for automatically arresting movement Iof said parts at a predetermined limit of movement.

l1. In a tube bending machine, a forming head having a profiled edge corresponding to the bend to be produced, a forming bar opposed ,Cto said profiled edge for pressing a tube against the same, tube clamping means mounted for movement with the forming head, means for rotating the forming head and tube clamping means through an arc of a circle, and means for arresting and reversing t-he movement of said parts to return them to their original positions after the desired bend has been produced.

12. In a tube bending machine, a forming head having a grooved edge for reception of a tube to be bent, the bottom of the groove being curved to correspond With'the desired bend, a forming bar opposed to said grooved edge for confining a tube in the groove, said forming bar being freely slidable tangenclamping means through an arc of a circle,

and means for arresting and reversing the and tube clamping means through an movement of said parts to return them to their original positions after the desired bend has been produced in the tube.

13. In a tube bending machine, a orming head having a profiled edge corresponding to the bend to be roduced, a forming bar o posed to said pro led edge for pressing a'tu e against the same, tube clamping means mounted for movement with the forming head, means for rotating the forming head and tube clamping means through an arc of a circle, a carriage for maintaining the forming bar in opposition to the forming head, means for moving thecarriage laterally with respect to the axis of the forming head while the latter is rotating, and means for arresting and reversing the movement of said parts to returnthem to their original positions after the desired bend has been produced in the tube.

14. In a tube bending machine, a ormin head having a grooved edge for receptionl o a tube to be bent, the bottom of the oove being curved to correspond with the esired bend, a forming bar opposed to said grooved edge for coniining a tube in the roove, said forming bar being freely slida le tangentially Awith respect to the ooved edge 'of the forming head, tube c amping means mounted for movement lwith 4the forming head, means for rotating the forming head arc of a circle, a carriage for maintaining the forming bar in opposition to the ormin head, means including a cam for moving tile carriage laterally with respect to the axis of the forming hea'd while the latter is rotating, and automatic means for arresting and manual means for reversing the movement of said 2parts to return them to their original position after the desired bend has been produced in the tube.

y15. In a tube bending machine thecombination of a formin vhead having an eccentrically curved pro le corresponding to that of the desired bend, a freely movable forming member opposed to the curved profile of said forming head and adapted to engage the opposite side of a tube to be bent against said curved profile, va carriage for im arting sli htly yieldingpressure to said freei) mov-` ab e forming member., means for esci ating the formin head about a fixed axis, a cam rotatable with the formin head and provided with a profile corresponding to that of the forming head, and means on the carria e for engaging said cam whereby to move sai carriage and freely .movable forming member laterally with respect to said fixed axis of oscillation. 1

16. In a tube bending machine the combination of a forming head having an eccentrically curved profile corresponding to that of the desired bend, a freely slidable forming bar opposed to the `curved profile of said forming head, means for oscillatingthe formi i I ingv head about a fixed axis, a carriage mo'v'- able toward pressure rollers mounted on the carriage -and adapted to engage the forming bar to force it toward the forming head, means for with# drawing said rollers from engagement with the forming bar, means for moving the carriage simultaneously with the forming head to compensate for eccentricity o the bend, and means for automatically arresting the movement of said parts at a predetermined limit. y

17. In a tube bendin machine, the combination with a movable orming member, of a tube clamping vise mounted upon said forming member, plurality of sets of vise jaws selectively interchangeable for gripping 'either an unbent tube or one which has been partlybent to form a bed-end or the like, and an varm mounted swingably upon the forming member for movement away from the jaws and hav\ing at its outer end means for clamping the jaws upon the tube. 18. A forming head for a tube bendingmal chine comprising a body member having aA curved edge proile corresponding with the desired bend, and flanges extending beyond said curved edge and for b' g therewith'a groove for thevreception of a tube to be bent, said flanges restrainingthe sides of a tube from bulgin during the bending operation, one of sai flanges being movable toward and away from the other flange, a plurality of actuating members for said movable flange, and means for simultaneously operating said actuating members.

19. A forming head for a tube bending ma-` chine comprising a body member having a curved edge profile cbrresponding with the desired bend, and flanges extending beyond. said curved edge and forming therewith a 4groove or the reception of a tube to be bent,

said flanges restrainingthe sides of a tube from bulging during the bending operation, one of said flanges being moyable toward and away from the other flange and being provided with a plurality of apertures, clamping posts -extending through said apertures vand in threaded engagement with the body member of the device, rock-arms carried bythe posts above the movable flange', links connecting the extremities of the adjacent rock-arms, and a hand lever connected to one of the rock-arms, movement of which is communicated to all the clamping posts through said links.

20. In a tube bending machine, the combination of a formin member having an eccentricallycurvedpro. e, a laterallymovable, op-

said vise adapted to include av and away fromsaid fixed axis,

sov

-aopy posing forming membemmeans for holding a to laterally move the opposing forming member correspondingly with the change of profile of the eccentrically curved forming member.l

5 N121. In a tube bending'machine, the combi# nation of a forming memberhaving an eccentrically curved prole, a laterally movable, opposing forming member, means for] holding a tube to be bent between the forming members, means for moving theeccentrically curved forming member about an axis of rotation, and a cam to laterally move the opposing orming member correspondingly with the change of prole of the eccentrieally curved forming member.

LOUIS FRANK, 

